Kinases currently represent one of the two largest classes of targets for drug discovery. In the field of oncology, the FDA's approval of the first kinase inhibitor, Herceptin, in 1998 started an extensive search for cancer drugs that target cellular signaling pathways. The search for new kinase inhibitors, critical tools in cancer therapy, often begins with the high throughput screening (HTS) of libraries followed by the evaluation of the potency of potential leads and their selectivity for a desired kinase. These studies require the widespread availability of efficient and affordable screens for kinase activity. A recent survey highlighted the most important features coveted by researchers in such a platform (Comley, Drug Discov World 2006, Winter 2006 Jul., 27). The survey indicated important features including affordability, non-radioactivity, label-free, antibody-free, generic (i.e., able to screen all classes of kinases), and utility for the study of large protein substrates. In addition, other preferred features included time-resolved or time-gated luminescence detection, and assays that measure the accumulation of ADP as opposed to the phosphorylation of a peptide or the displacement of a biomarker. None of the current commercial assays fulfill all of these needs. Moreover, none can be performed at higher concentrations of ATP, closer to the intracellular concentrations of 1-10 mM needed to study inhibitors of low-affinity kinases.